The invention relates to a load adjustment apparatus having an actuating element which controls the power of an internal combustion engine, is designed in particular as a throttle valve and is arranged on a control shaft, in which case the control shaft can be driven by means of a reversible actuating drive such that it can pivot between a minimum load position and a full load position, and having a single torsion spring, which is designed as a return spring to prestress the control shaft in the minimum load direction and as an emergency running spring to prestress the control shaft against an emergency running stop, the first end of which torsion spring is connected or can be connected to the control shaft while its second end is connected or can be connected to an arm of a supporting part which can move between a minimum load stop and the emergency running stop.
Load adjustment apparatuses of the type mentioned above are known in general by the name E-Gas, for adjusting the power of internal combustion engines in motor vehicles. By using a single torsion spring as an emergency running spring and as a return spring, the load adjustment apparatus has a particularly compact design, and is particularly light in weight.
A disadvantage of the known load adjustment apparatus is that the ends of the torsion spring must be attached in a complex manner to the control shaft and to the supporting part, since the torsion spring exerts actuating forces which act in both rotation directions of the control shaft. Furthermore, vibration in the motor vehicle can lead to the attachment of the torsion spring becoming loose. As a rule, the control shaft has a slot, into which the torsion spring is inserted, in order to attach the torsion spring to the control shaft.
It would be feasible to screw the second end of the torsion spring firmly to the supporting part. However, a load adjustment apparatus designed in such a way would be particularly costly. Furthermore, vibration can cause a screw to become loose, so that the torsion spring would then no longer be connected to the supporting part.